1. Technical Field
The present invention relates generally to the field of anesthesiology and to patient ventilating and anesthetizing and, more particularly, to a combination laryngeal mask airway with dual blocking and fluid removal features and method to ventilate a patient while isolating the trachea and the esophagus from each other.
2. Description of the Related Art
Airway devices are widely used in hospital surgical environments to provide respiratory assistance and to ventilate patents during medical procedures. Reference to ventilating includes providing breathable air or oxygen, for example, and removing gas, etc., e.g., exhalant exhaled by a patient, and providing anesthesia and/or other materials to and/or from the lungs of a patient. Ventilating also has the usual meaning as used in the field of medicine. The various gases, e.g., oxygen, air, anesthesia, etc., alone or in combination sometimes are referred to below collectively as gas mix.
While there are a multitude of airway devices currently on the market, one popular airway device is an endotracheal tube and another is a laryngeal mask airway (sometimes referred to in abbreviation as LMA). While the use of these devices is widespread, there are disadvantages associated with each of these devices.
As one example, endotracheal tubes are used to ventilate patients requiring anesthesia and/or respiratory assistance. An example of a conventional endotracheal tube is a plastic tube, which is inserted into a patient's mouth, is passed down the trachea through the vocal cords and is lodged in the trachea proximal (or above) to the lungs. The endotracheal tube may have a cuff or balloon portion surrounding the circumference of the endotracheal tube near the distal end that rests in the patient's trachea. After the endotracheal tube has been inserted properly, the cuff may be inflated to seal against walls of the trachea. Once sealed, positive pressure ventilation may be used to provide respiratory assistance and, if desired, anesthesia or other gas, gas mix, etc., to the patient though the endotracheal tube via a ventilator. The cuff provides a seal that tends to block liquids and solids from passing along the outside of the endotracheal tube between the tube and trachea walls and entering the patient's lungs.
While endotracheal tubes are ubiquitous in modern medicine, there are problems associated with the insertion of endotracheal tubes in patients. For example, there may be difficulty inserting the endotracheal tube into the proper position within the patient's trachea. A physician inserting the endotracheal tube may have difficulty viewing the trachea and there exists a possibility of inserting the endotracheal tube into the patient's esophagus, which leads to the patient's stomach rather than to the patient's lungs. If the tube is misdirected to the stomach, the lungs may not receive the proper air/oxygen mix. Additionally, the stomach may become filled with air possibly causing the patient to regurgitate, and the regurgitated material from the stomach may back flow and get into the patient's lungs. Another disadvantage of using an endotracheal tube is the invasive nature of intubation.
A laryngeal mask airway (LMA) overcomes many disadvantages associated with endotracheal tubes. An example of an LMA is disclosed in U.S. Pat. No. 6,634,354, issued Oct. 21, 2003 to Christopher, which is incorporated in its entirety by this reference. That LMA includes a hollow tube (sometimes referred to as a tubular guide, tube or guide) and a laryngeal mask. The laryngeal mask of the LMA is intended to fit in the mouth of a patient and to cover the two openings leading, respectively, to the esophagus and to the trachea, on the one hand, blocking the fluid path to and from the esophagus and stomach and, on the other hand, providing a fluid path to the trachea and lungs for ventilating the patient. The laryngeal mask may be positioned without requiring the physician to view the airway directly. The laryngeal mask has an inflatable cuff or rim area. Once the laryngeal mask is placed into the patient's mouth, the cuff can be inflated to seal against the walls of the inside of the mouth and, if positioned properly, to block flow to and from the esophagus. A rubber, plastic or like flexible, somewhat membranous support material extends from the cuff to form a recessed area, e.g., a space or volume, into which gas mix can be pumped through the tube or other instrumentality of the LMA to provide the requisite air and/or anesthesia to the patient. The tube is of relatively large diameter, as compared to the usually relatively narrower diameter passage of a conventional endotracheal tube, and such relatively large diameter facilitates gas mix and exhalant flow with relatively minimal interference, pressure drop, etc. The support material supports the cuff from the tube. Thus, the LMA can be used to supply gas mix to the recessed area and from there to the trachea. An advantage of an LMA is that the patient ordinarily does not have to be intubated with an endotracheal tube. If the LMA is not fully blocking flow to and from the esophagus, the gas mix primarily will flow to the lungs via the trachea because the trachea-lungs flow path generally has less resistance than the flow path from the esophagus to the stomach, and provided the pressure is not too great, the vast majority of the gas mix will flow into the lungs, and the stomach will not fill with the gas mix.
A drawback with the LMA is that the device cannot be used on all patients. For example, the device cannot be used on patients that are at risk for vomiting because if the laryngeal mask is not in the proper position, it does not fully isolate the airway to the trachea from the passageway to the esophagus. Thus, if the patient vomits during a medical procedure in which the LMA is used, the expelled fluid or solids could potentially flow from the esophagus to the trachea and enter the patient's lungs. An LMA ordinarily would not be used for patients that have eaten in the six hours prior to surgery, pregnant women, and trauma victims.
Thus, there is a need in the art to address the above mentioned and possibly other deficiencies and inadequacies of the prior art.